Discharge valve having a disk with a flushing aperture and an air intake aperture for a vacuum toilet

ABSTRACT

A discharge valve is disclosed for use in a vacuum toilet system having a waste receptacle defining an outlet and a sewer line placeable under partial vacuum. The discharge valve comprises a housing defining an inlet and an outlet and a rotatable discharge valve member disposed in the housing for selectively establishing fluid communication between the inlet and the outlet. A periphery of the disk valve member being formed with a series of ear teeth. An actuator is provided having a rotatable spur gear adapted to engage the periphery of the discharge valve member.

FIELD OF THE INVENTION

The present invention generally relates to toilets and, moreparticularly, to vacuum toilet Systems.

BACKGROUND OF THE INVENTION

Vacuum toilet systems are generally known in the art for use in bothvehicle and stationary applications. A vacuum toilet system typicallycomprises a bowl for receiving waste having an outlet connected to avacuum sewer line. A discharge valve is disposed between the bowl outletand vacuum sewer line to selectively establish fluid communicationtherebetween. The vacuum sewer line is connected to a collection tankthat is placed under partial vacuum pressure by a vacuum source, such asa vacuum blower. When the discharge valve is opened, material in thebowl is transported to the sewer pipe as a result of the pressuredifference between the interior of the bowl and the interior of thesewer line. Conventional vacuum toilet systems also include a source ofrinse fluid and a rinse fluid valve for controlling introduction ofrinse fluid into the bowl.

Conventional discharge valves are overly complicated to assemble. Suchvalves typically have a movable valve member linked to an actuator thatoperates the valve member between open and closed positions. The linkagebetween the valve member and the actuator often includes pivoting arms,joints, and other components which increase the complexity of valveassembly. In addition, gearing is often needed to slow the actuatorspeed to the desired valve actuation speed. Gear heads having four ormore stages are often required to obtain the desired speed. Each stage,however, introduces friction and other losses that decrease theefficiency of power transmission from the actuator to the valve member.

In addition, conventional discharge valves undesirably generate a highnoise level during a flush operation. When the discharge valve opens inresponse to a flush command, a significant amount of air, in addition towaste material and rinse fluid, is pulled into the sewer line. The airflows through a relatively narrow bowl outlet, which creates the noise.The noise may further be amplified by the shape of the toilet bowl.Apparatus is known for reducing the noise by introducing a secondarysource of air into the sewer pipe during a flush cycle. This apparatus,however, requires a separate valve and actuator, thereby increasing thecost and complexity of the toilet.

Still further, vacuum toilet systems in general and discharge valves inparticular are overly difficult and time consuming to maintain.Maintenance concerns are particularly significant in aircraftapplications, in which a number of sub-systems are installed on board.According to general practice in the airline industry, each sub-systemincludes one or more components which must be replaced in the event offailure, such replacement components being commonly referred to as linereplaceable units (LRUs). Presently, the entire vacuum toilet is definedas the LRU for the vacuum toilet system. As a result, an airline muststock one or more replacement toilets in the event of a toilet failure,so that the replacement toilet may be swapped in for the faulty toilet.A “bench test” is then performed on the faulty toilet to determine whichcomponents have failed in the toilet. The faulty components are thenrepaired or replaced (which may include significant disassembly andreassembly of the toilet) so that the repaired toilet may be reused onanother aircraft.

Each of the steps performed during a toilet repair is overly difficultand time consuming. To remove an entire toilet assembly from an aircraftrequires disassembly of at least four self-locking mounting fasteners,an electrical connection, a grounding strap, a potable water lineconnection, and a waste discharge pipe connection. Each connection maybe difficult to access, and may require a particular tool in order toloosen and disconnect. The same connections must then be reconnected forthe replacement toilet.

Even if it were possible to remove and replace a single toiletcomponent, it would be overly difficult and time consuming to do so.Removal of a component would require disconnection of several wires andpipes, and the components are often located in areas which are difficultto access. Furthermore, it would be difficult to diagnose whether onecomponent or several components had failed. There exists a multitude ofcombinations of simultaneous component failures, which may lead totrouble-shooting errors and the replacement or repair of non-faultycomponents.

Conventional discharge valves also use seals which are difficult toinstall and replace. As noted above, a discharge valve typically has amoving valve member disposed inside a housing. Seals are typicallyprovided inside the housing to prevent leaks between the valve memberand the upstream and downstream sides of the housing. As a result, thevalve housing must be disassembled to remove and replace a faulty seal.

Conventional vacuum toilets further fail to provide adequate feedbackregarding valve position. Conventional discharge valves are typicallydriven by an electric motor actuator having mechanical limit switchesand signal switches to control valve position. Such a switch is overlycomplicated to use and maintain. The switches must be precisely set totrigger at the appropriate time, and special tooling is often requiredto set the switch. In addition, by locating the switches in theactuator, they are subject to mechanical wear and contact erosion, whichmay alter the setting of the switch, thereby requiring re-setting.Furthermore, lubricant or other materials may migrate to the switches,causing switch failure. Most importantly, the conventional apparatus isunreliable since valve position is inferred from the actuator position.As a result, the conventional approach is not responsive to variousfailure situations where the actuator may be operable but the valve isnot, such as when the linkage connecting the actuator to the valve isbroken or defective.

SUMMARY OF THE INVENTION

In accordance with certain aspects of the present invention, a dischargevalve is provided for use in a vacuum toilet system having a wastereceptacle defining an outlet and a sewer line placeable under partialvacuum. The discharge valve comprises a housing defining an inlet and anoutlet, and a rotatable discharge valve member disposed in the housingfor selectively establishing fluid communication between the inlet andthe outlet, wherein a periphery of the valve member being formed with aseries of gear teeth. An actuator has a rotatable gear adapted to engagethe periphery of the discharge valve member.

In accordance with additional aspects of the present invention, adischarge valve is provided for use with a vacuum toilet system having awaste receptacle defining an outlet and a sewer line placeable underpartial vacuum. The discharge valve comprises a housing defining a flushvalve inlet fluidly communicating with the waste receptacle outlet, aflush valve outlet fluidly communicating with the sewer line, an airintake valve inlet fluidly communicating with ambient air, and an airintake valve outlet fluidly communicating with the sewer line. A movablevalve member is disposed in the housing and defining first and secondapertures, the valve member having a closed position in which the valvemember obstructs fluid communication between the flush inlet and flushoutlet, and between the air intake valve inlet and air intake valveoutlet, and an open position in which the first and second aperturesestablish fluid communication between the flush inlet and flush outlet,and between the air intake valve inlet and air intake valve outlet.

In accordance with further aspects of the present invention, a dischargevalve provided for use with a vacuum toilet system having a wastereceptacle defining an outlet and a sewer line placeable under partialvacuum. The discharge valve comprises a housing defining a flush valveinlet fluidly communicating with the waste receptacle outlet and a flushvalve outlet fluidly communicating with the sewer line. A rotatablevalve member is disposed in the housing and defines a first aperture.The valve member has a closed position in which the valve memberobstructs fluid communication between the flush valve inlet and theflush valve outlet, and an open position in which the first apertureestablishes fluid communication between the flush valve inlet and flushvalve outlet. A first seal is provided having a cylindrical wall sizedfor insertion from an exterior of the housing into the flush valveinlet, the cylindrical wall having a bottom edge adapted to engage andseal with the rotatable valve member.

In accordance with still further aspects of the present invention, adischarge valve is provided for use in a vacuum toilet system. Thedischarge valve comprises a housing defining a discharge valve inlet anda discharge valve outlet. A valve member is disposed inside the housing,the valve member being movable between a closed position in which thevalve member obstructs fluid communication between the discharge valveinlet and the discharge valve outlet, and an open position in whichfluid communication is established between the discharge valve inlet andthe discharge valve outlet. A sensor is provided for detecting positionof the valve member, the sensor being located outside of the housing.

In accordance with yet additional aspects of the present invention, adischarge valve is provided for use in a vacuum toilet system having abowl defining an outlet and a sewer line placeable under partial vacuum.The discharge valve comprises a housing defining a discharge valve inletadapted for fluid communication with the bowl outlet and a dischargevalve outlet adapted for fluid communication with the sewer line. A sealis disposed inside the discharge valve outlet, and a disk is disposedinside the housing and has first and second apertures connected by aslot. The first aperture, second aperture, and slot divide the disk intofirst and second disk halves, and the disk is rotatable between a closedposition, in which one of the first and second disk halves engages theseal to obstruct fluid flow, and an open position in which one of thefirst and second apertures is aligned with the seal to allow fluid flowtherethrough. The slot allows the first and second disk halves todeflect in response to partial vacuum at the discharge valve outlet tomore reliably engage the disk with the seal in the closed position.

Other features and advantages are inherent, in the apparatus claimed anddisclosed or will become apparent to those skilled in the art from thefollowing detailed description and its accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views of a vacuum toilet incorporating adischarge valve in accordance with the present invention.

FIG. 2 is a schematic diagram of the vacuum toilet of FIG. 1.

FIG. 3 is an enlarged perspective view of a valve set, including thedischarge valve, incorporated into the vacuum toilet of FIG. 1.

FIGS. 4A and 4B are perspective views of the discharge valve.

FIG. 5 is an exploded perspective view of the discharge valve.

FIG. 6 is a side elevation view of an alternative discharge valve memberembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vacuum toilet 10 is illustrated in FIGS. 1A, 1B and 2 having a valveset 8 with a discharge valve 70 in accordance with the presentinvention. The vacuum toilet 10 includes a bowl 36 for receiving wastematerial connected to the valve set 8. In the preferred embodiment, thebowl 36 is supported by a frame 20 to form a replaceable bowl assembly,as described in greater detail in commonly owned and co-pending U.S.patent application Ser. No. 09/713,861, entitled “Toilet Bowl Assembly”,incorporated herein by reference. The vehicle is provided with a sewerline 11, a vacuum tank 13 connected to the sewer line 11, and a vacuumsource (not shown) for placing the vacuum tank 13 under partial vacuumpressure. The vehicle further includes a source of rinse fluid 15connected to a rinse fluid supply line 19. At least one rinse fluiddispenser, such as nozzles 46, is provided inside the bowl 36 fordirecting rinse fluid over the surface of the bowl. A rinse fluid pipe35 connects the valve set 8 to the nozzles 46.

As shown in FIG. 3, the valve set 8 comprises four sub-components: thedischarge valve 70, a rinse valve 72, a flush control unit (FCU) 74, andan actuator 76. The preferred valve set is described in greater detailin commonly owned and co-pending U.S. patent application Ser. No.09/713,870, entitled “Valve Set for a Vacuum Toilet”, incorporatedherein by reference. While the discharge valve 70 is described andillustrated herein as integrated into the valve set 8, it will beappreciated that the discharge valve 70 may be provided as a separate,independent component, without departing from the spirit and scope ofthe present invention.

The discharge valve 70 includes a discharge valve housing 78 dividedinto two halves 78 a, 78 b. As best shown in FIGS. 4A and 4B, thehousing 78 includes a pair of inlets 79, 80 formed in the housing half78 a aligned with a pair of outlets 81, 82 formed in the housing half 78b. The housing 78 further defines a chamber for receiving a dischargevalve member, such as valve disk 83. An axle 84 is attached to the valvedisk 80 and has two ends 84 a, 84 b. Holes are formed in the housinghalves 78 a, 78 b sized to receive the axle ends 84 a, 84 b,respectively, so that the disk 83 is supported for rotation about theaxle 84. In accordance with certain aspects of the present invention,the periphery of the disk 83 is formed with gear teeth 85, and a pair ofapertures 86, 87 are formed through the disk 83. The apertures 86, 87are spaced so that both register simultaneously with the associatedinlet/outlet pairs 79/81, 80/82 as the disk 83 rotates. In theillustrated embodiment, the apertures 85, 86 and associated inlet/outletpairs 79/81, 80/82 are spaced 180 degrees apart.

According to the illustrated embodiment, the inlet 79 is connected toone end of a transfer pipe 44, with the other end of the transfer pipebeing attached to an outlet 42 of the bowl 36. In the preferredembodiment, the transfer pipe 44 includes a fitting 47 (FIG. 1A) adaptedto frictionally and sealingly engage the bowl outlet 42, so that thetransfer pipe 44 may be quickly and easily attached and removed from thebowl outlet 42. An air intake check valve 45 is attached to the otherinlet 80, and is oriented to allow fluid to flow into the inlet 80 whilepreventing fluid from discharging out of the check valve 45. A U-shapedoutlet pipe 12 (FIG. 1B) has a first end connected to the outlet 81 anda second end connected to the outlet 82. The outlet pipe 12 further hasa branch 17 leading to a discharge pipe 21. In the preferred embodiment,the branch 17 includes a pair of spaced pins and the discharge pipe 21includes a pair of J-shaped slots positioned to engage the pins, so thatthe discharge pipe 21 is removably attached to the branch 17.Furthermore, when the pins and J-shaped slots are spaced 180 degreesapart, the discharge pipe 21 may be positioned for either right- orleft-handed discharge simply by rotating the discharge pipe 21 beforeattachment, without requiring changes to the other toilet components.The free end of the discharge pipe 21 is adapted for releasableconnection to the sewer line 11, such as with a clam shell coupling (notshown).

In operation, when the disk apertures 86, 87 are aligned with theinlet/outlet pairs 79/81, 80/82, the discharge valve 70 not onlytransfers waste from the transfer pipe 44 to the sewer line 11, but alsopulls additional air into the sewer line 11 through the air intake checkvalve 45. The additional air intake reduces noise that is normallygenerated during a flush.

The actuator 76 is provided for driving the valve disk 83. As best shownin FIG. 4A, the actuator 76 includes a spur gear 90 enmeshed with thegear teeth 85 formed about the periphery of the disk 83. The spur gear90 is mounted to a rotatable shaft 92, and a drive is provided forrotating the shaft 92. The FCU 74 is operably coupled to the actuator 76to control operation of the actuator. According to the illustratedembodiment, the disk 83 may be rotated in a single direction by ninetydegree increments to open and close the discharge valve 70.Alternatively, the disk 83 may also be reciprocated back and forthacross a ninety degree arc to open and close the valve 70, or the disk83 may be controlled in other manners according to other disk designsand layouts.

In accordance with additional aspects of the invention, external sealsare provided for preventing fluid leaks between the disk 83 and valvehousing 78. As best shown in FIG. 5, four seals 95 are provided eachhaving a cylindrical wall 96 sized for insertion into the inlets 79, 80and outlet 81, 82. Each seal 95 further includes a lip 97 that engagesan outside surface of the housing 78 to limit travel of the cylindricalwall 96 into the housing 78. The cylindrical walls 96 have a heightsufficient to engage and seal with the disk 83 when fully inserted intothe housing 78. The sealing engagement between the seals 95 and disk 83is maintained during rotation of the disk 83 to prevent fluid leakage.The seals 95 may be inserted and removed from the outside of the housing78, thereby obviating the need to disassemble the discharge valvehousing 78 for a seal replacement. The seals 95 are preferably formed ofultra-high molecular weight polyethylene.

Vacuum pressure present in the outlet pipe 12 will act on a closed disk83 to pull the disk 83 toward the seals 95 inserted in the outlets 81,82, thereby energizing the seals. Accordingly, it will be appreciatedthat the seals 95 inserted in the inlets 79, 80 do not technically sealwith the disk 83, but instead help to center the disk 83 inside thehousing 78. In an alternative disk embodiment illustrated at FIG. 6, asplit disk 183 is provided to further enhance the seals formed at theoutlets 81, 82. The disk 183 is formed with a pair of apertures 186, 187connected by a slot 180. The slot 180 divides the disk 183 into two diskhalves 184, 185 that are more easily flexed in a direction normal to theplane of the disk 183 (or into and out of the page as shown in FIG. 6).Because of the increased flexibility, the disk halves 184, 185 are moreresponsive to the vacuum pressure in the outlet pipe 12, so that theoutlets 81, 82 are more reliably sealed.

The FCU 74 comprises a housing 150 attached to the discharge valvehousing half 78 b opposite the rinse valve 72 (FIG.3). The housing 150encloses one or more circuit boards 155 (FIG. 5) for controllingoperation of the discharge valve 70 via the actuator 76. Because the FCU74 is located proximal to the actuator 76, the number of wires neededbetween the FCU 74 and actuator 76 is reduced.

In addition, the FCU housing 150 houses a position sensor fordetermining the position of the disk 83. As best shown in FIG. 4A,magnets 152 are attached to the axle end 84 b of the disk 83. The axleend 84 b extends into the FCU housing 150, so that the magnets 152 arepositioned proximal the control board. Hall effect switches 154 areprovided directly on the circuit board for sensing the magnets 152 andthus determining the rotational position of the disk 83. In theillustrated embodiment, a pair of magnets 152 are attached to the axleend 84 b, and a pair of hall effect switches 154 are attached to thecircuit board. The switches 154 actuate between on and off positionsdepending on the proximity of the magnets, thereby indicating theposition of the disk 83. As a result, the position of the disk 83 isdirectly sensed rather than inferring disk position based on actuatorposition. In addition, the switches 154 are located inside the FCUhousing 150 and are therefore isolated from contamination due tolubrication or other material.

From the foregoing, it will be appreciated that the discharge valve ofthe present invention has a simplified valve member drive due to thegear teeth formed about a periphery of the discharge valve member. Inaddition, the discharge valve simultaneously opens the drain andsecondary air passages, and may be operated in a single direction.Furthermore, the seals are easily removed from an exterior of the valve,thereby facilitating replacement.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications would be obvious to those skilled in theart.

What is claimed is:
 1. A discharge valve for use with a vacuum toiletsystem having a waste receptacle defining an outlet and a sewer lineplaceable under partial vacuum, the discharge valve comprising: ahousing, defining a flush valve inlet fluidly communicating with thewaste receptacle outlet, a flush valve outlet fluidly communicating withthe sewer line, an air intake valve inlet fluidly communicating withambient air, and an air intake valve outlet fluidly communicating withthe sewer line; and a rotatable valve member disposed in the housing anddefining first and second apertures, the valve member having a closedposition in which the valve member obstructs fluid communication betweenthe flush inlet and flush outlet, and between the air intake valve inletand air intake valve outlet, and an open position in which the firstaperture establish fluid communication between the flush inlet and flushoutlet, and the second aperture establish fluid communication betweenthe air intake valve inlet and air intake valve outlet.
 2. The dischargevalve of claim 1, in which the valve member comprises a disk.
 3. Thedischarge valve of claim 1, in which the movable valve member issupported for rotation inside the housing, and the apertures are spacedsubstantially 180 degrees apart with respect to a rotation axis of thevalve member.
 4. The discharge valve of claim 3, in which the valvemember is rotated in a single direction between open and closedpositions.
 5. The discharge valve of claim 3, in which the valve memberis rotated in ninety degree increments between open and closedpositions.
 6. The discharge valve of claim 3, in which the valve memberis reciprocated in two directions between open and closed positions. 7.The discharge valve of claim 1, further comprises a first seal having acylindrical wall sized for insertion from an exterior of the housinginto the flush valve inlet, the cylindrical wall having a bottom edgeadapted to engage and seal with the rotatable valve member.
 8. Thedischarge valve of claim 7, further comprising a second seal having acylindrical wall sized for insertion from an exterior of the housinginto the flush valve outlet, the cylindrical wall having a bottom edgeadapted to engage and seal with the rotatable valve member.
 9. Thedischarge valve of claim 7, in which the first seal comprises ultra-highmolecular weight polyethylene.
 10. The discharge valve of claim 8,further comprises a first air intake seal having a having a cylindricalwall sized for insertion from an exterior of the housing into the airintake valve inlet, the cylindrical wall having a bottom edge adapted toengage and seal with the rotatable valve member.
 11. The discharge valveof claim 10, further comprising a second air intake seal having, acylindrical wall sized for insertion from an exterior of the housinginto the air intake valve outlet, the cylindrical wall having a bottomedge adapted to engage and seal with the rotatable valve member.
 12. Adischarge valve for use in a vacuum toilet system having a wastereceptacle defining an outlet and a sewer line placeable under partialvacuum, the discharge valve comprising: a housing defining a dischargevalve inlet fluidly communicating with the waste receptacle outlet and adischarge valve outlet fluidly communicating with the sewer line arotatable valve member disposed in the housing and defining first andsecond apertures, the valve member having a closed position in which thevalve member obstructs fluid communication between the discharge valveinlet and outlet, and between an air intake valve inlet whichcommunicates with ambient air and an air intake valve outlet whichcommunicates the sewer line, and an open position in which the firstaperture establish fluid communication between the discharge valve inletand outlet and the second aperture establish fluid communication betweenthe air intake valve inlet and outlet; and a sensor for detectingposition of the valve member, the sensor being located outside of thehousing.
 13. The discharge valve of claim 12, in which at least onemagnet is attached to the valve member, and the position sensorcomprises a hall effect sensor positioned to detect the position of themagnet.
 14. The discharge valve of claim 13, in which the valve membercomprises a disk supported for rotation about an axle.
 15. The dischargevalve of claim 14, in which the at least one magnet is attached to anend of the axle.
 16. The discharge valve of claim 15, in which axle endextends into a flush control unit, and in which the ball effect sensoris housed in the flush control unit.
 17. The discharge valve of claim16, in which the hall effect sensor is provided directly on a circuitboard.
 18. A discharge valve for use in a vacuum toilet system having abowl defining an outlet and a sewer line placeable under partial vacuum,the discharge valve comprising; a housing defining a discharge valveinlet adapted for fluid communication with the bowl outlet and adischarge valve outlet adapted for fluid communication with the sewerline; a seal disposed inside the discharge valve outlet; a disk disposedinside the housing having first and second apertures connected by aslot, the first aperture, second aperture, and slot dividing the diskinto first and second disk halves, the disk being rotatable between aclosed position, in which one of the first and second disk halvesengages the seal to obstruct fluid flow, and an open position, in whichone of the first and second apertures is aligned with the seal to allowfluid flow therethrough; wherein the slot allows the first and seconddisk halves to deflect in response to partial vacuum at the dischargevalve outlet to more reliably engage the disk with the seal in theclosed position.
 19. The discharge valve of claim 18, in which thehousing further defines an air intake inlet and an air intake outlet,and in which a second seal is disposed inside the air intake outlet,wherein one of the first and second disk halves also engages the secondseal when the disk is in the closed position, and wherein the other ofthe first and second apertures is also aligned with the second seal whenthe disk is in the open position.
 20. The discharge valve of claim 19,in which a periphery of the disk is formed with a series of gear teeth.21. An integrated valve set for use in a vacuum toilet system having awaste receptacle defining an outlet and a sewer line placeable underpartial vacuum, the integrated valve set comprising: a discharge valvehaving a housing with an inlet in fluid communication with the wastereceptacle outlet and an outlet in fluid communication with the sewerline, and a rotatable valve member disposed in the housing and definingfirst and second apertures, the valve member having a closed position inwhich the valve member obstructs fluid communication between the inletand outlet, and between an air intake valve inlet which communicateswith ambient air and an air intake valve outlet which communicates thesewer line, and an open position in which the first aperture establishfluid communication between the valve housing inlet and outlet and thesecond aperture establish fluid communication between the air intakevalve inlet and outlet; and a flush control unit operably to thedischarge valve and having a housing attached to the discharge valvehousing, the flush control unit including a position sensor fordetecting the position of the discharge valve member.
 22. The integratedvalve set of claim 21, in which a magnet is attached to the dischargevalve member, and in which the position sensor comprises a hall effectswitch responsive to a position of the magnet.
 23. The integrated valveset of claim 21, in which the rotatable discharge valve member comprisesa disk having an axle with an end disposed inside the flush control unithousing, and in which the position sensor detects a rotationalorientation of the axle.
 24. The integrated valve set of claim 23, inwhich a magnet is attached to the axle end, and in which the positionsensor comprises a hall effect switch responsive to a position of themagnet.
 25. The integrated valve set of claim 21, further comprising anactuator adapted to engage and move the discharge valve member.
 26. Theintegrated valve set of claim 21, in which the toilet system furthercomprises a source of rinse fluid and the waste receptacle has a rinsefluid dispenser associated therewith, and in which the integrated valveset further comprises a rinse fluid valve having an inlet in fluidcommunication with the rinse fluid source, an outlet in fluidcommunication with the rinse fluid dispenser, and a rinse fluid valvemember.
 27. The integrated valve set of claim 26, in which the rinsefluid valve member is mechanically coupled to the discharge valvemember.